In the related art, there is a known endoscope in which a plurality of illumination optical systems are provided around an observation optical system in order to illuminate a field of view of the observation optical system with uniform brightness (for example, see PTL 1). The light-distribution irregularities of illumination light in the field of view become particularly problematic when performing magnified observation by bringing a distal-end surface of the endoscope close to an object at a distance that is equal to or less than 2 mm. In other words, because the distance between the distal-end surface of the endoscope and the object is very small, it is difficult to make the illumination light coming from the illumination optical systems reaches the entire field of view of the observation optical system. In the case of PTL 1, the layout of the illumination optical systems at the endoscope distal-end surface is designed so as to make improvement in the light-distribution irregularities during magnified observation.